fix: 修改Spacing和WingBlank组建文档

Author: hy

packages/core/src/Spacing/README.md

@@ -1,15 +1,13 @@
 Spacing 间距
 ---
-
-![](https://user-images.githubusercontent.com/57083007/146733395-aed1e7d6-724e-4e8e-9491-511253b9c0ff.png)<!--rehype:style=zoom: 33%;float: right; margin-left: 15px;-->
-
+组件上下留一点间距
 ### 基础示例
 
-```jsx
-import { Fragment } from 'react';
+```jsx  mdx:preview
+import React,{ Fragment } from 'react';
 import { Spacing, Button } from '@uiw/react-native';
 
-function Demo() {
+const Demo = () => {
   return (
     <Fragment>
       <Button>按钮之间的间距</Button>
@@ -20,6 +18,8 @@ function Demo() {
     </Fragment>
   );
 }
+export default Demo
+
 ```
 
 ### props

packages/core/src/WingBlank/README.md

@@ -1,23 +1,26 @@
 WingBlank 两翼留白
 ---
 
-布局控件
-
-![](https://user-images.githubusercontent.com/57083007/146734301-dd0b7af2-c823-463c-ab8a-075ef0ffdc48.png)<!--rehype:style=zoom: 33%;float: right; margin-left: 15px;-->
+左右两边空出一点距离
 
 ### 基础示例
 
 <!--DemoStart--> 
-```jsx
+```jsx  mdx:preview
+import React,{Component} from 'react';
 import { View, Text } from 'react-native';
 import { WingBlank, Button } from '@uiw/react-native';
 
-export default function Demo() {
-  return (
-    <WingBlank>
-    </WingBlank>
-  );
+class Demo extends Component {
+  render() {
+    return (
+      <WingBlank>
+        <Text>两翼留白两翼留白两翼留白两翼留白两翼留白两翼留白两翼留白两翼留白两翼留白两翼留白两翼留白两翼留白两翼留白两翼留白两翼留白两翼留白两翼留两翼留白两翼留白两翼留白两翼留白</Text>
+      </WingBlank>
+    );
+   }
 }
+export default Demo
 ```
 <!--End-->